There has heretofore been known an optical connector with optical fibers, what is called a fanout code, in which a plurality of buffered optical fibers are branched from a multi-fiber optical connector while single-fiber optical connectors are respectively connected to ends of the branched buffered optical fibers (see, e.g., Patent Literature 1). FIG. 1 is a diagram schematically showing a structure of a conventional optical connector with optical fibers. As shown in FIG. 1, the conventional optical connector with optical fibers includes a multi-fiber optical connector 510, a plurality of buffered optical fibers 520 branched from the multi-fiber optical connector 510, and single-fiber optical connectors 530 attached to ends of the respective buffered optical fibers 520.
Each of the buffered optical fibers 520 includes a tube 521 and a bare optical fiber 522 housed in the tube 521. Each of those bare optical fibers 522 is housed loosely within the tube 521. Ends of the tube 521 and the bare optical fiber 522 near the single-fiber optical connector 530 are fixed to a ferrule 531 in the single-fiber optical connector 530. Furthermore, ends of the respective tubes 521 near the multi-fiber optical connector 510 are fixed to a connector housing 511 of the multi-fiber optical connector 510. Ends of the respective bare optical fibers 522 near the multi-fiber optical connector 510 are fixed to a ferrule 512 in the multi-fiber optical connector 510.
When an optical connector with optical fibers thus constructed is under a low temperature for an environmental test or the like, the tubes 521 and the bare optical fibers 522 shrink. The tubes 521 are formed of a material that has a higher rate of shrinkage (coefficient of thermal expansion) than the material of the bare optical fibers 522. Therefore, the tubes 521 shrink to a larger extent relative to the bare optical fibers 522. As a result, as shown in FIG. 2, the bare optical fibers 522 relatively project from the tubes 521 into the multi-fiber optical connector 510. Thus, the bare optical fibers 522 are bent within the multi-fiber optical connector 510. If the bare optical fibers 522 are thus bent, the optical characteristics of the bare optical fibers 522 are deteriorated due to the bend loss. When the buffered optical fibers 520 become long in length (e.g., over 50 cm in length), the amount of shrinkage of the tubes 521 increases. Therefore, the deterioration becomes more significant.